Angular 2 why asterisk (*)

Question

In angular 2 document, * and template, we know that the *ngIf, *ngSwitch, *ngFor can be expanded to ng-template tag. My question is:

I think the ngIf or

Answer 1

From Angular docs:

Structural directives are responsible for HTML layout. They shape or reshape the DOM's structure, typically by adding, removing, or manipulating elements.

As with other directives, you apply a structural directive to a host element. The directive then does whatever it's supposed to do with that host element and its descendants.

Structural directives are easy to recognize. An asterisk (*) precedes the directive attribute name as in this example.

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